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5x^2+18y^2-30x+72y+27=0 into standard form of circle

1 Answer

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The circle equation 5x² + 18y² - 30x + 72y + 27 = 0 represented in standard form is (x - 3)²/18 + (y + 2)²/5 = 1

Converting the circle equation to standard form

From the question, we have the following parameters that can be used in our computation:

5x² + 18y² - 30x + 72y + 27 = 0

Rewrite as

5x² + 18y² - 30x + 72y = -27

Group the equation by the variables

5x² - 30x + 18y² + 72y = -27

So, we have

5(x² - 6x) + 18(y² + 4y) = -27

Complete the square on x and y

So, we have

5(x - 3)² + 18(y + 2)² = -27 + 45 + 72

This gives

5(x - 3)² + 18(y + 2)² = 90

Next, we divide through by 90

(x - 3)²/18 + (y + 2)²/5 = 1

Hence, the standard form is (x - 3)²/18 + (y + 2)²/5 = 1

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